Tucking mechanism for wrapping machines



NOV. 10, 1959 w LUCZEK ETAL TUCKING MECHANISM FOR WRAPPING MACHINES 3Sheets-Sheet 1 Filed Jan. 1'7, 1957 WA TOR EYS INVENTOR WALTER LUCZEKCEDRIC E. CROSS WM 2? Fillvlllt l r kll NOV. 10, 1959 w ucz EI'AL I2,911,779

TUCKING MECHANISM FOR WRAPPING MACHINES Filed Jan. 17, 1957 3Sheets-Sheet 2 INVENTOR WALTER LUCZEK CEDRIC B. CROSS BY A w ATIO NEYSFIG. 2

NOV. 10, 1959 w, ucz EIAL TUCKING MECHANISM FOR WRAPPING MACHINES 3Sheets-Sheet 3 Filed Jan. 17, 1957 INVENTOR TUCKING MECHANISM FORWRAPPING MACHINES Walter Luczek, Indian Orchard, and Cedric B. Cross,

Monson, Mass., assign'ors to Package Machinery Company,.East Longmeadow,Mass., a corporation of Massachusetts Application January 17, 1957,Serial No. 634,716 3 Claims. (Cl. 53-378) The present invention relatesto wrapping machines of the type wherein articles are continuouslyadvanced in a straight line as the wrapping operation is carried out andmore particularly to tucking mechanism forarticles partially wrapped inthis type of machine.

The machine disclosed .in application Serial No. 439,- 682, filed June28, 1954, now U.S. Patent No. 2,810,246, is illustrative of the type ofWrapping machine referred to above. While that type of machine aifordsrates of operation hitherto unobtainable, it does not lend itself to theuse of conventional techniques in tucking the ends of a wrapperencircling the article. It is, therefore, the object of our invention toprovide improved tucking mechanism for wrapping machines which willenable such machines to take full advantage of the inherently high ratesof operation which they possess. Another object of our invention isfound in the simple, reliable and economical tucking mechanism forwrapping machines generally.

Our invention resides in a novel combination of parts wherein theleading portion of a wrapper extending from and encircling an articlerides against and is foldedinwardly by one tucker member while a secondtucker member is moved in proper timed relationshipto overtake and foldinwardly the trailing portion of the extended wrapper as the article iscontinuously advanced in a straight line and wherein the tucking membersare relatively thin and project from a pair of rotors. v

The various objects of the invention and its detailed novel aspects willbe more readily apparent from a reading of the following description oftwopreferred embodiments, makingreference to the accompanying drawings,and the particular novelty thereof .pointed out in the appended claims.

In the drawings: a

Fig. 1 is a side elevation, with certain frame members omitted, showingthe portion of a wrapping machine in which the tucking operation iscarried out by our improved mechanism;

Fig. 2 is a section taken generally on the lineII-Jl in Fig. 1;

Figs. 3 through 7 inclusive are plan views of thetucking members seen inFig. 1 showing the progressive positions which they assume in performinga tucking operation;

Fig. 8 is an end view of a tucked package.

For illustrative purposes our tucking mechanism is herein disclosed inassociation with a high speed wrapping machine as disclosed intheabove-referred to application. It will be understood, however, that thisin no way indicates that our invention is restricted to use with thisparticular type of wrapping machine. Many wrapping machine componentsseen in that application (and particularly Fig.'21 thereof) will befound in equivalent form in Fig. 1, as will now be described.

As seen in Fig. 1 and as in the mentioned application, partially wrappedarticles A are yieldingly gripped by jaws 20, 22 extending from endlessroller' chains 24,

nited States Patent which chains are driven bysprockets 26 and then.pass around a second set of sprockets, not shown. The chains 24 areguided by upper and lower rails 27 and the jaws 20, 22 have lugs 29which ride on fixed ledges 31 (see also Fig. 2) so that articles A willbe advanced rectilinearly as in the straight line path illustrated.Articles gripped in the jaws 20, 22 have a draped wrapper W, thedepending ends of which are encircled about the article as it passesabove a rotating bail member 28 and onto a ledge 30 all in a novelmanner fully described in the named application. The bail member 28rotatesin timed relation to the movement of the articles inasmuch as itis driven through a sprocket 32 and chain 34 which is powered by asprocket 36 fast upon the same shaft 38 as the sprockets 26. a

The tucking mechanism of the present invention is driven in timedrelation to the movement of the articles carried in the jaws 20, 22 bybeing driven from a common power source. That is, a sprocket 38 isarranged to rotate with the bail sprocket 32 as by securing bothsprockets on a shaft 40 which shaft is journaled in the side frames ofthe wrapping machine. A desired rate of operation of the tuckingmechanism may be obtained by passing a roller chain 42 around a twodiameter sprocket 44. From the second diameter of the sprocket 144 aroller chain 46 passes around a sprocket 48 secured toa shaft 50 whichis journal'ed on the side frames (Fig.2) and which is the main powershaft for rotating our tucking mechanism. t

In order to perform tucking operations, simultaneously. on both ends ofan article we have provided two tucking units which are indicatedgenerally by the reference characters 52, 54 in Fig. 2. Each unit, .byway of-illustrating our invention, comprises two superposed rotors 56,58 which respectively carry blades or tuckers 60, 62. Since the units 52and 54 are identical in all respects a detailed, description of only oneunit will be given,=w hich description may be applied to either of theunits and like reference characters will be found on the correspondingparts .of the two units.

The rotors 56, 58 are rotated in the same direction but at diiferentspeeds .by the now to be described arrangement which provides anoperative connection witlrthe main power shaft (for the tuckingmechanism) 50. The rotors 56, 58 (Fig. 2) are carried, through meansmore fully described below, on a box-like frame .64 which is slidablymounted on a transverse shaft 66 securedat its ends to the side framesof the machine. A threaded shaft 68 is journaled on the side frames andexteriorly provided with a hand wheel 70. The shaft 68 is threadablyreceived by a collar 72 on the frame 64, right and left hand threads arerespectively provided onthe opposite ends of the shaft 68 so that thetuckingunits 52 and 54 may be simultaneously adjusted inwardly oroutwardly to bring the rotor blades 60, 62 into a desired transverserelation with the wrapper W which is to be tucked.

With this transverse adjustment in mind, it will be seen that we haveprovided a spline connection, employing a key 73 (-Fig. 2) between theshaft 50 and a bevel gear 74 which is rotatably mounted on abracket 76bolted to the under side of the frame 64. The gear 74 meshes with anddrives a second bevel gear 78 keyed to a verticalshaft .89 which isjournaled in the frame 64. Also secured to the shaft 80 and withintheframe 64 are spur gears 82, 84. Axial movement of the shaft 80 isprevented by the hubs of the gears 78 and 84 bearing against oppositesides of the lower portion of the frame 64. The spur gear 84 meshes witha matinggear6 which is pinned to a second vertical shaft. 88 which isalso journal'ed on the frame 64. The upper rotor 56 is adjustablysecured to the upper end of the shaft 88 as by a set screw 90 and thuswill rotate with that shaft at a 3 rate determined, in part, by theratio between the gears 84 and 86.

The spur gear 82 meshes with a mating gear 92 formed on the lower end ofa sleeve 94 which is rotatably mounted on the shaft 88 and journaled inthe upper portion of the frame '64. The lower rotor 58 is adjustablysecured to the upper end of the sleeve 94 as by a set screw 96 and thuswill rotate with that sleeve and at a rate determined, in part, by theratio between the gears 82 and 92. Axial movement of the shaft 88 isprevented by the l91ub of the gear 86 and a collar 98 secured to thesleeve With the above arrangement it is possible to vertically positionthe rotor blades 60 and 62 so that their paths of rotation willintersect the path of travel of the portion of a wrapper W which extendsbeyond each end of the article about which it is encircled as isillustrated in Figs. 2 and 3. Preferably the blades 60 and 62 should.pass as closely as possible to the horizontal centerline ofthe articles,and this can be obtained by adjustment of the set screws 90 and 96 toproperly locate the rotors 56, 58 on the shaft 88 and sleeve 94respectively. The vertical adjustment of the rotors may be facilitatedby a collar 99 which is secured to the sleeve 94 by a set screw 100. Thecollar 99 also facilitates angular adjustment of the rotors 56, 58 whenthe set screws 90 and 96 are loosened to bring the rotor blades 60, 62into a desired relative position so that they will rotate in propertimed relation to the movement of an article as will be more apparentfrom the description set forth below of the tucking operation.

As mentioned, the rotor blades 60, 62 rotate in paths which intersectthe path of movement of the wrapper extension or extended portion of awrapper W and preferably as close as possible to the horizontalcenterline of the article. In this embodiment of our invention it isalso preferable that the rotor blades 60, 62 be very thin as well asbeing very close together in a vertical sense. To further particularize,the features of this embodiment of our invention are ideally suited,though not necessarily limited to the formation of an end tuck of thetype illustrated in Fig. 8 as will be more readily apparent from thefollowing description of their operation.

The start of the tucking operation for this type of tuck is seen in Fig.3. The lower rotor blades 62 have, in Figs. 3 through 7, been shaded tofacilitate their identification in those figures. An article A is beingadvanced along a straight line in uninterrupted fashion past the rotors56, 58 as is indicated by the arrow associated with the article A.During the intersecting portions of their paths, the rotor blades 60, 62move in the direction indicated by the respective arrows so that eachblade has a component of motion extending in the same direction as themovement of the article A. The rate of rotation of the rotor 56 is suchthat the article will overtake the blade 60a as will be appreciated bycomparing the relative positions of the article and rotor blade 60a inFigs. 3 and 4. The rotor 58 is rotated at twice the rate as the rotor 56so that the rotor blade 62a will overtake the article A as it isadvanced and engage the trailing portion of the extended wrapper W ascan be appreciated from again comparing Figs. 3 and 4 and will beparticularly seen in Fig. 5. Also in Fig. 5 it will be seen that as thearticle A continues to overtake the rotor blade 60a the leading portionof the extended wrapper is folded inwardly in a progressive manner aswill be more fully appreciated from viewing Fig. 6. Simultaneouly thefaster rotating blade 62a is folding the trailing portion of theextended wrapper inwardly as the article continues its uninterruptedadvancement. Fig. 7 shows the position of the blades 60a and 62a as thetucking operation nears its completion. The timing of the rotor bladeswith respect to the advancement of the article allows them to swingclear of the tucked wrapper end after the tucking operation is completedand as the article continues its rectilinear advancement towards furtherinstrumentalities which will complete the wrapping operation.

This last-described relationship of the rotor blades is illustrated inFig. 3 by the blades 60b and 62b and the article A as the completedtuck, seen in Fig. 8, is formed. We have found it preferable to provideadjacent and beyond the rotors 56 and 58 retaining bars 102 and 104which temporarily restrain the extended wrapper end in its tuckedrelation until the above-mentioned further instrumentalities can disposeof the tucked end in the manner desired. These further instrumentalitiesare not essential to the present invention but may include a heatsealing bar which seals the tucked end and then furtherinstrumentalities which fold the sealed end underneath the package andsecure it by heat sealing to the underneath side of the package tocomplete the packaging or wrapping operation. During the tuckingoperation, the article has been positively gripped by the jaws 20, 22 tomaintain, at all times, a proper relationship between the article andthe blades 60, 62, all of which demonstrates the preferability of thistype of conveyor.

While we have found that it is preferable that the rate of rotation ofthe rotor 58 be twice that of the rotor 56 and that the slower movingrotor have twice the number of blades as the faster moving rotor, andwhile We are able'to perform with this arrangement, a successful tuckingoperation at a very rapid rate of speed it will be appreciated thatother numbers of blades and other speed ratios could successfully beemployed so long as the sequence of relative motions between theextended wrapper and the rotor blades 60a and 62a as illustrated, inFigs. 3 through 7, are maintained. Further note should be taken that ithas been found preferable for the lower rotor to be the slower'rotorwhere the overlapped portion of the wrapper is slid along the ledge 30.

From the above it will be readily appreciated that we have providedtucking means which are capable of operation at extremely high rates ofspeed and that in doing so' we have uniquely arranged one tucker whichis engaged by the leading portion of an extended wrapper to fold thatportion inwardly and a second tucker which is movable into and out ofthe path of the extended wrapper with a component of movement in thesame direction as and at a rate faster than the rate of the article sothat the second tucker overtakes and folds the trailing portion of theextended wrapper. The movements of the tuckers are set in predeterminedtimed relation to the movement of the article so that the leading andtrailing portions of the extended wrapper may be folded or tucked in thedesired manner, whereby successive partially wrapped articles are tuckedat a very rapid rate.

Having thus described our invention what we claim is novel and desire tosecure by Letters Patent of the United States is: l

1. In a wrapping machine, means for rectilinearly advancing inuninterrupted fashion and in predetermined spaced relationship articlesencircled by a wrapper extending beyond the article; tucking mechanismcomprising two coaxially mounted rotors having relatively thin bladesdisposed in closely adjacent, spaced parallel'planes which planes arealso parallel to the horizontal plane through which: the articles areadvanced with the path of movement of the rotor blades intersecting thepath of movement of the extended wrapper, means for continuouslyrotating said rotors in predetermined timedrelation to the movement ofan article and in a direction such that their blades are moving in thesame general direction as the extended wrapper when their paths ofmovement intersect, the speed of rotation of one rotor being such thatthe peripheral rate of its blade is less than the rate of the articleand .the speed of rotation of the other rotor being such that theperipheral rate of its blade is faster than the article whereby theleading portion of the extended wrapper will overtake and be foldedinwardly by the blade of the one rotor and the blade of the other rotorwill overtake the trailing portion of the extended wrapper and fold itinwardly all as the article is moving. a

2. In a wrapping machine tucking mechanism as set forth in claim 1wherein said one rotor has twice the number of blades as said otherrotor.

3. In a wrapping machine, a conveyor for rectilinearly advancing inuninterrupted fashion and in predetermined spaced relationship articlesencircled by a wrapper the ends of which extend beyond'the article, saidconveyor comprising jaws for gripping the leading and trailing sides ofeach wrapper-encircled article to positively maintain it in said spacedrelationship, and tucking mechanism comprising a tucking unit on eachside of the conveyor for simultaneously tucking opposite ends of theextended wrapper, each of said tucking units including two multi-bladedrotors disposed in closely adjacent parallel planes which planes arealso parallel to the horizontal plane through which the articles areadvanced as well as being closely adjacent the horizontal centerline ofthe articles, said rotors being superposed to rotate about a common axiswith the paths of movement of the rotor blades intersecting the path ofmovement of the extended wrapper, means for rotating said rotors inpredetermined time relationship to the movement of an article and in adirection such that their blades are moving in the same generaldirection as the extended wrapper when their paths intersect, one ofsaid multi-bladed rotors having a given number of equi-radially spacedthin blades, the speed of said one rotor being such that the peripheralrate of its blades is less than the rate of the articles, the other ofsaid multi-bladed rotors having half the number of blades as said onerotor which blades are thin and equi-radially spaced around said otherrotor, the speed of said other rotor being such that the peripheral rateof its blades is greater than the rate of the article, whereby theleading portion of the extended Wrapper will overtake and be foldedinwardly by one of the blades on said one rotor and one of the blades onsaid other rotor will overtake the trailing portion of the extendedwrapper and fold it inwardly, the two tucking units thus performing thetucking operation on both ends ofthe wrapper-encircled article as it iscontinuously advanced.

References Citedin the file of this patent UNITED STATES PATENTS1,350,608 Harriss Aug. 24, 1920 2,144,265 Milmoe Ian. 17, 1939 2,625,778Wood Jan. 20, 1953 2,634,564 Bergstein Apr. 14, 1953

